Serologic Tests for Lyme Disease Yield Disparate Results

When serum samples were tested for anti-Borrelia antibodies using eight commercially available ELISAs and five immunoblot assays, intertest agreement was only modest.

Current guidelines for diagnosing Lyme disease include a two-tier testing algorithm: an enzyme-linked immunosorbent assay (ELISA) for detecting anti-Borrelia antibodies, followed by immunoblot confirmation of positive ELISA results. Commercially available tests are based on sonicated whole-cell Borrelia antigens, recombinant antigens, or a mixture of the two.

To compare the performance of these assays, researchers in the Netherlands tested serum samples for anti-Borrelia antibodies using eight commercial ELISAs and five immunoblots (4 commercial, 1 investigator-made). The 89 samples were from 59 patients with suspected Lyme disease, 14 healthy controls, and 16 patients with syphilis or Mycoplasma pneumoniae infection — conditions associated with highly cross-reactive antibodies.

Of the 89 samples, 35 (39%) tested negative — and 16 (18%) tested positive — on all ELISAs. The remaining 38 (43%) tested positive on one to seven ELISAs. The proportion of samples with positive results on any one ELISA ranged from 34% to 59% for patients with suspected Lyme disease and from 0% to 38% for patients with cross-reactive antibodies. Samples from healthy controls almost always had negative ELISA results.